LAKE COUNTY – The health of Clear Lake is something local environmentalists have tackled for years, succeeding in protecting Rodman”s Slough, Anderson Marsh, and tentatively Mt. Konocti”s Black Forrest, among other efforts.
Some local residents lately have pondered, “What is the current environmental condition of our lake?” Patrick McCaffrey, a Lakeport resident who moved to the county seven years ago from Sonoma County, wonders whether it is safe to swim in Clear Lake, and has heard about mercury poisoning and algae growth that has affected the lake for decades.
“I personally won”t swim in the lake because I”m worried about the pollution. And I know there has been pollution from mercury and run-off, but I haven”t heard anything about the current situation. Is the lake healthy, or not?” asks McCaffrey.
According to UC Davis researchers, who since 1997 have been studying mercury levels and ecosystems of Clear Lake, the health of Clear Lake has improved since the early 1990”s, but still has a ways to go.
“It”s certainly safe to swim in,” said UC Davis research scientist Tom Suchanek, who says that untreated lake water is drinkable despite the mercury levels that sparked the California Office of Environmental Health Hazard Assessment to issue a health advisory for consumption of fish. The maximum amount of fish consumption should be limited to one per month for the average person, according to COEHH.
The pollution of the lake dates back to sulfur and mercury mining in the late 1800”s, when mercury was used in gold mining.
In 1949, DDT was sprayed on the lake to control gnats. The biocide then appeared throughout the food chain, dropping the grebe population from 1,000 nesting pairs to almost zero. The declining grebe population was noted in Rachel Carson”s 1962 book Silent Spring, a publication many believe spearheaded the environmental movement. Today, the grebe population on Clear Lake has climbed to approximately 10,000, and thriving pairs of bald eagles, pelicans, osprey, and heron also point to signs of recovery.
The long-time algae problem in Clear Lake also dates back to the 1800”s, when early settlers used water-filtering wetlands for farming, cutting off an important internal filtering system for the lake”s sediments and nutrients. With wetlands having been reduced from 9,000 acres to 2,000 acres, nutrients from erosion, pesticides, and fertilizers piled into the lake, feeding a disproportionate overgrowth of blue-green algae. This growth can create layers which become trapped and rotten, creating that famous “lake smell” locals have come to expect each summer.
Residents may have noticed, however, that that smell has decreased in recent years, as well as the thickness of the algae. Local resident Lucinda Wilson recalls the algae being so thick one summer during the 1970”s that “turtles could walk on it in Jago Bay.”
Fortunately, turtles walking on water will likely be a thing of the past, as plans by local agencies to curb overloading nutrients into the lake have been steadily underway.
The reclaiming of Rodman Slough wetlands on the north end of the lake at the confluence of Middle and Scott”s Creeks as well as efforts to replant native tule plants will allow nutrients to be filtered from the lake as well as bolster habitats for Clear Lake wildlife.
A factor in increased mercury levels throughout the decades was found to be the Sulfur Bank Mine on the eastern shores of Clear Lake. In 1991, the mine was declared a Superfund site (one of the nation”s 1,240 most contaminated toxic waste sites) due to public outcry that the mercury levels in fish discovered by Fish and Game biologist Larry Week in the 1970s were directly tied to the mine.
For decades, the water from the 90-foot-deep Herman Pit which sits above lake level seeped through mine rubble located near the lakes shore, picking up sulfuric acid and mercury before entering the lake.
And while remediation efforts have largely cleared the rubble, added vegetation, and improved the looks of the mine, there is some debate over whether or not these efforts have resulted in curbing the mercury leaks from the mine.
Another debate in the county is over whether or not the nutrient TMDL (Total Maximum Daily Load as determined by the US Environmental Protection Agency) is justified, because the data is based on tests conducted many years ago, according to Victoria Brandon, chair of the Lake County Sierra Club chapter.
“As far as the algae and water weed concerns, there are a lot more weeds than algae now, and the weeds are not nearly as bad for the ecosystem as the algae. The mercury really is a concern, but there are some positive things in the future-the Middle Creek restoration project just passed through Congress-which will help with the nutrients and add about another 1000 acres of wetlands,” said Brandon.
“Rodman”s Slough and Anderson Marsh are the only substantial wetlands left 80 percent have gone. But the Middle Creek and Scotts Creek projects are really, really promising. It”s a public safety issue as well, because the levees which would be removed are aging and crumbling-all of that is a big concern,” said Brandon.
According to Brandon, the health of Clear Lake is one of three main conservation projects on the Sierra Club”s agenda, including preservation of Mt. Konocti and the Black Forrest, and managing growth in the county wisely. An additional project underway is to stop the spraying of herbicides on Lake County”s roadsides. “A healthy lake is really important for the community,” said Brandon.
According to Brandon, the bill that would protect the Middle and Scotts Creek projects passed late in the legislative session, but an extra complication exists.
“It depends on another bill being passed. Robinson Rancheria land was going to be flooded by the levees coming down, this is their trust land, so they would want to transfer their trust status to another property they own. This is going to require additional legislation, so it is really tied up in that,” said Brandon.
Contact Elizabeth Wilson at ewlison@record-bee.com
